Sequestering agent for uranyl chelation: a new family of CAMS ligands
摘要:
The synthesis of new dipodal bis-sulfocatecholamide uranophiles is presented. Their binding abilities for uranyl cation were determined by UV spectro photometry in aqueous media under various pH conditions and further studied by H-1 NMR analysis of the resonance signal of both aromatic protons of the sulfocatecholamide groups. The results showed that the efficiency of these hydrosoluble chelating agents depends on the nature of the spacers. Each ligand shows a more or less pronounced affinity for uranium. The best receptor is the ligand CYCAMS 5d obtained as a mixture of cis/trans isomers, which achieves the best compromise between rigidity and steric hindrance. (C) 2008 Elsevier Ltd. All rights reserved.
High Yield Selective Acylation of Polyamines: Proton as Protecting Group
作者:Asmik Oganesyan、Iris A. Cruz、Roberto B. Amador、Nohemy A. Sorto、Jose Lozano、Carlos E. Godinez、Jaime Anguiano、Heather Pace、Ghiwa Sabih、Carlos G. Gutierrez
DOI:10.1021/ol702206d
日期:2007.11.1
An advance in the selective acylation of polyamines having identical or similar amine functions is reported. While nucleophilicity differences between the various amine functions are slight, the corresponding conjugate acids exhibit pK(a) values over a significant range. We have used proton as polyamine protecting group: the monoamine resulting from single deprotonation of a polyammonium compound has allowed for high yields of selective acylation.